Lumped-Parameter Equivalent Circuit Models of a Multi-Winding Transformer for DAB and MAB Applications

Dual active bridge (DAB) and multiple active bridge (MAB) converters tracks attention of industrial and transportation applications such as aircrafts, high-speed trains and electric vehicles. The key energy interface components in DAB and MAB is the high-freuqency 2-winding or multi-winding transformers. This paper proposes multi-winding transformer equivalent circuit models used for DAB and MAB converters, including T-$\pi$-shaped model and $\pi$-shaped model. T-$\pi$-shaped model may be used to analyze copper loss, iron loss and iron core saturation. $\pi$-shaped model could be used to achieve average power transfer equations accurately together with ZVS discussions. These models was derived by math calculation and verification by simulations and experiments with different modulation conditions.